1. Technical Field
The present disclosure relates generally to devices and methods for delivery of ingestible materials to a user's body and more particularly to mechanical devices and methods for delivering ingestible materials to a user's gastrointestinal tract through a feeding tube.
2. Background Art
In many situations, a person or animal can be unable to orally consume ingestible materials such as food products, nutritional supplements or medications and must be intubated with a feeding tube for delivery of such products. Intubation generally involves placing a feeding tube through the mouth or nose of the patient beyond the esophagus and extending to a position in the user's gastrointestinal tract, typically the stomach. A conventional feeding tube typically includes a tube inlet located outside the user's body and a tube outlet positioned inside the user's body. Ingestible materials can be delivered to the user's gastrointestinal tract by injecting such materials into the feeding tube inlet. The ingestible material can then move through the tube and can be ejected from the tube at the tube outlet for consumption by the user.
In many applications, it is desirable to inject the ingestible material through the feeding tube into a user's body using a manual, plunger-driven syringe device. One exemplary application involves the use of a nasogastric feeding tube. A nasogastric feeding tube generally extends through the patient's nostril, nasopharynx, oropharynx, and esophagus leading into the user's stomach or intestine. Devices for delivering ingestible materials to a user through the nasogastric tube inlet using a plunger-driven delivery device, or syringe, are known in the art. Such conventional devices generally include a device having a longitudinal cylindrical chamber, or barrel, defining an interior cavity for storing an ingestible material such as a food product, nutritional supplement or medication. A plunger is typically disposed in the barrel for pushing the ingestible material from the chamber through a device orifice. Conventional devices of this type can include a tube fitting located on or near the device orifice for coupling the device to the nasogastric feeding tube inlet.
One problem associated with conventional plunger-driven feeding tube delivery devices involves incomplete advancement of the ingestible material through the feeding tube. Generally, the feeding tube can have a length from about 10-100 cm, depending on the size of the patient and the particular application. When ingestible material is injected into the nasogastric tube, the material must be pushed through the entire length of the tube to the tube outlet inside the user's body. In some applications, the volume of the ingestible material is less than the interior volume of the feeding tube, and a plunger-driven delivery device is not capable of pushing the entire ingestible material volume completely through the feeding tube using only one stroke of the plunger. Instead, using conventional devices and methods, some ingestible material may remain in the feeding tube after the plunger has been fully depressed in a single stroke, thereby forming an occlusion of ingestible material in the tube and forcing the user to perform additional steps to completely evacuate the tube into the user's stomach. Such additional steps can take many forms and can include disconnecting the delivery device from the tube, retracting the plunger to refill the chamber with a flushing fluid or alternatively providing a new syringe device filled with a flushing liquid, attaching the refilled device to the tube inlet, and injecting the flushing liquid into the tube to force the occlusion of ingestible material through the tube into the user's stomach.
Another problem associated with conventional plunger-driven feeding tube delivery devices includes the growth and development of microorganisms in the feeding tube following passage of the ingestible material through the tube. In some applications, the ingestible material includes chemical compounds that can promote the growth of bacteria in the interior of the tube. Conventional devices can leave ingestible material deposits on the interior wall of the tube following delivery, creating regions that may support bacterial growth. Such bacterial growth can pose health risks to the user as subsequent injections through the tube will likely introduce the bacteria into the user's body. Additionally, because some conventional syringe or plunger-driven devices do not fully evacuate the feeding tube following operation of the plunger, a biofilm can form on the interior of the feeding tube.
Thus, there is a continuing need in the art for improvements in plunger-driven feeding tube delivery devices and methods for introducing ingestible materials into a user's body through a feeding tube.